Abstract: The present invention discloses a method and system for controlling a power supply by delivering stable output voltage independent of load. The control system includes a sensor for sensing a state variable, a fuzzy logic controller for generating a control action, and an actuator for regulating the power supply in accordance with the control action. The fuzzy logic controller generates a fuzzy logic knowledge base using low-level fuzzy logic controllers and a mode selector in one embodiment and a fuzzy logic proportional integral controller in another embodiment. The generated fuzzy logic knowledge base is compiled in a look-up table and is used to quickly and efficiently control a power supply device such as a resonant converter.

Abstract: A method for automated control of a steam turbine prewarming procedure employs fuzzy logic to generate a control signal for a turbine regulatory function, such as steam supply. The method includes the steps of determining a plurality of turbine condition parameter signals; generating a plurality of regulatory control directions; generating a weighting factor to be assigned to each of said regulatory control directions by means of a fuzzy inference calculation in accordance with an operator-selected fuzzy logic profile, and applying the weighting factors to the regulatory control directions to produce the turbine regulatory function control signal. The turbine regulatory function control signal is applied to a respective function controller in the steam plant such that the selected turbine prewarming profile is implemented.